| 摘要 |
PURPOSE: A high strength steel plate and a manufacturing method thereof are provided to micronize a primary austenite crystal grain as much as possible and rapidly cooling in a controlled rolling process, thereby reducing material difference in the thickness direction and obtaining excellent low temperature impact tenacity on the center of the steel plate. CONSTITUTION: A method for manufacturing a high strength steel plate includes the following steps of: reheating a slab plate at a temperature of 1000-1200°C; primarily rolling the reheated slab plate at an austenite recrystallization region; secondarily rolling the primarily rolled slab plate at a finishing delivery temperature of 700-850°C; and cooling the secondarily rolled slab plate at a temperature of 450-600°C. [Reference numerals] (AA) Start; (BB) End; (S110) Reheat a slab (1000-1200°C); (S120) First rolling; (S130) Second rolling (finishing: 700-850°C); (S140) Cooling (450-600°C) |
